Slow log on and response for server

Currently we are migrating users over to Tiger and authenticating to OD.
Some of our users are still in Panther and are not yet part of OD so to log onto the available X-Raid drives I have set up a generic user which they can log in with.
Yesterday it seemed to take a long time for users to log in using the generic user- it was very slow to let them log on.
Also when looking at the server through ARD to actually move things around the server desktop pretty much grinded to a halt.
I do have the server set up for Link Aggregation and I will say that the ARD problem was noticed late last week but didn’t seem to affect anyone.

I decide to reboot the server to see if that helped but when I did all I could get to was to the desktop but with no dock and no icons- it basically just froze there.
After trying to reboot a few times I then unplugged the two Ethernet cables on the back and plugged them back in-rebooted and eventually got back on the desktop with the icons and dock.

What could have happened here? Is it something in our network or is it just inherit of the OS X server?

Any logs I should be checking out and if so what should I be looking for?

Thanks.